Thread-tensioning device



April 7, 1931.- j R. WUERTZ 7 5 THREAD .TENSIONING DEVIGE Filed March21, 1929 Hudam WuErz,

Juve f 01,

Patented Apr. 7, 1931 UNITED STATES RUDOLPH WUERTZ or READING;rENNsYLvANIA THREAn-TENsroNrNG DEVICE Application filed March 21', 1929.Serial No. 348304.

This invention relates to an improved means for tensioning the feedngthreads or Fig. 1 is a view diagrammatically indicati ing the inventionin connection with certain parts of a -straight knitting machine, thepassing thread being shown as deflectedly engaged by different rings ofthe relatively enlarged tensioning device, so as to deterninedly tensionthe same, more or less as determined by the number of defiections thuspro- Vided; the manner of engaging or disengaging an additional spiralring for varying the tension being indicated by a dotted-line showing ofthe thread.

F ig. 2 is a separate plan View of the spiralcoil tensioning device.

As diagrammatically indicated in Fig. 1, the thread from bobbin b, isdrawn over a top bar 0 of the machine, in feedingly extending it to thethread carrier (l on carrier bar e and thence to the needles f;Intervening devices commonly provided are not indicated,

and the top bar c, as shown, is utilized for conveniently attaching myimproved ten- 5 sioning device so as to arrange it in the path of thefeeding thread; The essential purpose is to enable the operator toquickly and easily adjust the tension accurately a-s need develops, bymerely looping` the running thread upon determined ones of the coilringsof the device as hereinafter fully described.

As indicated this tensioning device 'is simply formed from a singlepiece of spring wire; one end of 'which is bent to form a clip 11adapted as shown to engage the machine bar c and resiliently hold themain portion 12 in the path of the thread. This main portion 12 isfol-med as a spiral coil having spaced-apart spiral rings 12 12' 12which are alternately engaged the feeding yarn-;the spread of theserings, or the pitch ,of 'the spiral coil, being preferably varied toenable great nicety of'tension adjustment, as will` clearly appear from'the differentts angular defiections of the thread thusefi'ectedasshoWninFigl. i

The manner of engaging the running 'thread with each determinedring"of'the spiralcoil, is indicat-edin Fig.'"l in 'connec- 00 tion with theeffecting of the added deflection of the bobbin thread which isindicated by the dotted-line showing;-the thread being merely carriedunder the spiral coil 12 and thrown over the top into engagement with(30. the adjacent spiral coil 12 so as to add the slight angulardeflection under coil 12 which deflection slightly increases the tensionprovided by the similar engagements and defiections of the thread withcloserp spaced rings 12 as indicated in the full line showing. i

The thread extending to the point of fabrication, is selectively engagedWith any two or more of the rings 12 12 312 of the coil, as determinedby the number and angles of the deflections required to efiect desiredtension; the thread in each case being merely thrown past an interveningring or rings into r engagement With an advanced ring as indicated, sothat said intervening ring or rings i will deflect it from the straightline of the engaged rings, with a greater or less angle of deflectionand resulting friction deter mined by the spread of the suecessively en-35 i gaged rings. Thisvery simple method of efl'ecting requiredtensioning permits of varying the same with the great nicety andquickness required for practically satisfactory operation and quality ofproduct. e

What Iclaim is:

1. A feeding-thread tensioning device consisting of a continuous lengthof wire one end of which is shaped to form a frame-engaging clip and themainportion of which v is spirally coiled in the path of the feedingthread to deflectingly engage the latter substantially as described. e

2. A feeding-thread tensioning device consisting of a continuous lengthof wire one end 100 of which is shaped to form a frame-engaging clip'and the main portion of which is formed into a spira'l coil of variedptch, said coil being arranged in the path of the feeding thread andadapted to' varyingly deflect separated engaging portions of the latter.

3. A feeding-thread tensioningdevice conssting of a continuous length ofWre one end of which is provided with a franre-engagng support and themain portion of which is formed into a spiral 'eoil adapted to freeiyeXtend from said support With its holloW aXis arranged in the path ofthe feeding thread and its convolutions adapted to, de-

fiectingy i engage the' letter.

"4. A feedng-thread tensionng device con sisting of a oontinuous lengthof Wire one end of .which is provided With a frame-engagng support andthe main portion of which is iorrned into a spiral coil of Varied pitchadapted to freely extend from said support With its hollow aXs arrangedin the path of the feedng thread and its co'nvolutions adapted todefietngly engage the latter.

, In testimony Whereof, 1 afiX ny signature. I

RUD OLPH `WUERTZ.

